flycanvas.java

源码为科学出版社出版的英文<java设计模式>(影印版)所用的所有例子程序

package FlyFolders;

import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.border.*;
import javax.accessibility.*;

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;

public class FlyCanvas extends JxFrame
implements MouseMotionListener {
    Folder folder;
    Vector names;
    FolderFactory fact;
    final int Top = 30, Left = 30;
    final int  W = 50, H = 30;
    final int VSpace = 80, HSpace=70, HCount = 3;
    String selectedName="";
//-------------------------------  
    public FlyCanvas() {
        super("Flyweight Canvas");

        loadNames();
        JPanel jp = new JPanel();
        getContentPane().add(jp);
        setSize(new Dimension(300,300));
        addMouseMotionListener(this);
        setVisible(true);
        repaint();
    }
//-------------------------------  
    private void loadNames() {
        names = new Vector();

        fact = new FolderFactory();
        names.addElement("Alan");   
        names.addElement("Barry");  
        names.addElement("Charlie");
        names.addElement("Dave");   
        names.addElement("Edward"); 
        names.addElement("Fred");   
        names.addElement("George"); 
//     selectedName = "Charlie";  
        selectedName = "";
    }
//-------------------------------
    public void paint(Graphics g) {
        Folder f;
        String name;

        int j = 0;      //count number in row
        int row = Top;  //start in upper left
        int x = Left;

        //go through all the names and folders
        for (int i = 0; i< names.size(); i++) {
            name = (String)names.elementAt(i);
            if (name.equals(selectedName))
                f = fact.getFolder(true);
            else
                f = fact.getFolder(false);
            //have that folder draw itself at this spot
            f.draw(g, x, row, name);

            x = x + HSpace;          //change to next posn
            j++;
            if (j >= HCount) {       //reset for next row
                j = 0;         
                row += VSpace;
                x = Left;
            }
        }
    }
//-------------------------------  
    public void mouseMoved(MouseEvent e) {
        int j = 0;      //count number in row
        int row = Top;  //start in upper left
        int x = Left;

        //go through all the names and folders
        for (int i = 0; i< names.size(); i++) {
            //see if this folder contains the mouse
            Rectangle r = new Rectangle(x,row,W,H);
            if (r.contains(e.getX(), e.getY())) {
                selectedName=(String)names.elementAt(i);
                repaint();
            }
            x = x + HSpace;          //change to next posn
            j++;
            if (j >= HCount) {       //reset for next row
                j = 0;         
                row += VSpace;
                x = Left;
            }
        }
    }
    public void mouseDragged(MouseEvent e) {
    }

//-------------------------------  
    static public void main(String[] argv) {
        new FlyCanvas();
    }
}